This copy is for your personal non-commercial use only. To order presentation-ready copies of Toronto Star content for distribution to colleagues, clients or customers, or inquire about permissions/licensing, please go to: www.TorontoStarReprints.com

Thirteen days ago the first-degree murder trial in the death of university student Qian “Necole” Liu began with the defence attempting to enter a manslaughter plea.

On Tuesday, the defence announced it would call no evidence.

Accused Brian Dickson will not take the stand, as is his right.

That means closing arguments on Friday and judge’s charge to the jury next Monday — one of the shortest murder trials in memory, just six days of prosecution-summoned evidence in all.

Three pathologists have taken the stand but none was able to say, definitively, how 23-year-old Liu died, found face-down and almost completely naked in her basement apartment just south of York University on April 15, 2011.

Article Continued Below

The first, Dr. Jeff Tanguay, who conducted Liu’s autopsy, testified that in his best estimation cause of death was mechanical asphyxia, which could have been caused by neck or chest compression blocking the airway. The second, Dr. Christopher Milroy, did a peer review of Tanguay’s report and agreed with the conclusion in his evidence on Monday, noting petechia — small hemorrhages in the eyes, the result of blood supply being obstructed — was consistent with, say, an arm or hand pressing against the throat. Tuesday, Dr. Kristopher Cunningham, a cardiovascular pathologist, told court there was nothing in his subsequent examination of the heart that indicated pre-existing disease, structural, microscopic or genetic damage to the organ.

Cunningham disputed the suggestion by defence lawyer Robert Nuttall — raised with the other others as well — that Liu could have succumbed to a rare condition called commotio cordis, arising from a concussion to the heart. This is sometimes seen in young athletes who suddenly drop dead after sustaining a strong blow to the chest.

“Blunt trauma can cause the heart to become electrically unstable, going into arrhythmia,” causing death within a matter of minutes if the heart isn’t “rebooted,” Cunningham agreed. But in this case, there was no indication that had happened.

“The heart didn’t have any bruising. No bruising on the chest or bruising on the soft tissues beneath the chest.”

Nuttall has raised the scenario of a large man sitting on Liu’s chest, thereby obstructing the airways, and that the victim’s positioning, with head tucked or cricked, could explain bruising of the internal neck muscles.

What the jury has heard, repeatedly, are the astronomically long odds of DNA evidence collected from Liu’s body originating from anyone other than the defendant. In the exacting language of the courts, this is described as genetic profiling that “could not exclude” Dickson as the source of male DNA found on Liu’s breast “to a high degree of probability” — one in 25 trillion. Swabs taken from Liu’s abdomen and upper groin, containing semen, were calculated to a match with Dickson of one in 2.7 quintillion. That’s 387 million times the global population of 7 billion.

But Nuttall, in his brief opening address last week, emphasized to the jury that “this is not a who-done-it case. This is a what-happened-case. The mechanism of death is very significant in proving whether the Crown has made its case.”

Earlier, in front of the jury pool, Nuttall had tried to enter a plea of manslaughter with Justice Anne Molloy for his client. This was immediately rejected by the Crown. Dickson, 32, has pleaded not guilty to first-degree murder.

It has become known as The Webcam Murder, ever since news emerged shortly after Liu’s body was discovered that the events unfolding late that night three years ago were captured by a laptop camera on her computer as the student conversed online with her ex-boyfriend in Beijing. Xian Meng testified last Friday that he and Liu were communicating both via Skype and QQ, the Chinese version of MSN. He watched as Liu responded to a knock, rising from her desk and speaking through the closed door before opening it to a male who was wearing a blue T-shirt and shorts. Meng said Liu spoke with the man who stood in her doorway, then handed him her cellphone. The man then muscled his way into the room, even as Liu said “no, no,” first in Cantonese and then in English. Meng watched helplessly as Liu was pushed to the floor and beyond view of the camera.

“Next I heard two muffled bangs and from then I heard no more sound from Qian Liu.”

But Meng could hear heavy breathing, after which a male, naked from the waist down, approached the computer and turned it off.

Horrified, Meng went into a chat-room Liu used in search of anyone who might know her address so that police could get there. His pleas weren’t answered until the social media tom-toms eventually roused the building superintendant the following morning.

Dickson was a first-floor tenant in that building. In a four-hour interview with police April 19, 2011, he denied killing Liu or kissing her or embracing her, though admitting he’d been in the woman’s apartment briefly on a previous evening and had run into her in the basement kitchen earlier on the night of April 14.

Detectives conducting surveillance on Dickson were later able to retrieve two discarded cigarette butts from which DNA was obtained. The genetic fingerprint was then matched to swab samples taken from Liu. No semen was found internally, only on Liu’s skin.

While the jurors heard reference to the DNA throughout the trial, the science of it — mathematical probabilities — was not presented as evidence until Tuesday, with Melissa Kell, a forensic biologist with the Centre of Forensic Sciences, taking the stand. Kell provided a compact tutorial on the DNA recovered from Liu’s body, including foreign DNA under her finger nails. No other foreign DNA other than that matching Dickson to a degree of high probability was discovered. “The semen has been deposited since she last washed herself.”

Kell tested blood found on a blue T-shirt belonging to Dickson, which police had seized from his room. Odds that the blood came from someone other than Liu, she said, are one in 140 quadrillion.

Another of the building’s residents testified that he saw a man in the basement kitchen around 2 a.m. That man said hello before going into the washing machine room, although he carried no laundry.

More from the Toronto Star & Partners

LOADING

Copyright owned or licensed by Toronto Star Newspapers Limited. All rights reserved. Republication or distribution of this content is expressly prohibited without the prior written consent of Toronto Star Newspapers Limited and/or its licensors. To order copies of Toronto Star articles, please go to: www.TorontoStarReprints.com